package Exams.MeituanPack.test01_sqrtSum;

import java.util.Scanner;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            double n = sc.nextInt(), m = sc.nextInt();

            double res = 0;
            for(int i = 0; i < m; i++){
                res += n;
                n = Math.pow(n, 0.5);
            }
            System.out.println(String.format("%.2f", res));
        }
        sc.close();

    }
}
